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Mike Brown and his research group explore the solar system using telescopes on the Earth and in space at wavelengths from the ultraviolet through the millimeter. We are interested in trying to tell the story of the evolution of the solar system, in discovering unseen distant planets, in swimming the oceans of Europa, and in playing with massive data sets. And drinking coffee.You can read more about Mike Brown, explore the research into which he and his group are engaged, see details on his online and Caltech classes, find out about his writing, public speaking, and media appearances, or continue here for the latest updates.You can see more frequent updates on Mike Brown on Bluesky at

Mike Brown



Free Online Class: Science of the Solar System

Science of the Solar System is a top-rated online science class at a high school-college level. Read how you can use it for your class or just for yourself.

Mike Brown at TED
Mike Brown at TED Credit: TED

Planet Nine at TED

The National Academy of Sciences, the Kavli Foundation, and the Simons Foundation, recently sponsored the first full-day science focused TED conference. Planet Nine took the TED stage.


Caltech Center for Comparative Planetary Evolution

Caltech has just launched the 3CPE, an interdisciplinary center which merges the fields of astronomy, geology, and biology to answer these questions about the origin and evolution of planetary systems and their biospheres. Mike Brown will be the inaugural director of the Center.

Interested in being a postdoc? We would love for you to consider our group!

Interested in being a graduate student? We would love for you to consider our department!

Planet Nine

The latest on Planet Nine

We finally understand the dynamics of how distant eccentric planets affect the solar system that a complete theoretical treatment is possible. You can read all about it. It's a bit complicated. You can instead read the more accessible version.


Salt on Europa

Graduate student Samantha Trumbo led a project using the Hubble Space Telescope to search for salts on Jupiter's moon Europa. Her paper shows the first definitive detection of sodium chloride -- table salt! -- on the satellite, and suggests that the oceans of Europa may me more like our own than previously thought.

How I Killed Pluto and Why It Had It Coming

How I Killed Pluto and Why It Had It Coming

My 2010 memoir of the discovery of Eris, the reclassification of Pluto, and my lack of sleep in between is, officially, an award winning best seller. It's also been translated into many languages that I can't read, including German, Japanese, Russian, and Korean.

Find it (or order it) at your favorite independent book store or online.